Gasket and method of manufacturing same



Aug. 13, 1940. G. 'r. BALFE 2,211,045 GASKET AND muon oF uAuumcw'unmasnm Filed nec. 27. 1957 s2 sheets-skien 2' Patented Aug. 13, 1940 4 t Iy UNITEDv STATES -PATENT OFFICE I GASKET AND METHOD 0F MANUFACTUR- INGSAME George T. Balle, Detroit, Mich., assigner to Detroit Gasket, &Manufacturing Company, Detroit, Mich., a corporation of MichiganApplication neeeinber 27,1937, ser-iai Ne. 181,947

` 19 claims. (c1. isi-33.1)

This invention relates to gaskets and methods 'tively unclinched cushionmaterial between the of manufacturing the same. tangs so vthat there ispresent a variable com- The primary object of the invention istoinpression of the vcushion material between the crease thecompressibility of gaskets of the Balfe tangs independently of theextent to which such n type, for example, as shown in the patent tocushion material is maintained clinched `or com- 5 George T. Balie,1,776,140, September 1,6, 19,30, pressed by the tangs themselves.without objectionably (1) varying the overall Such a' constructionprovides throughout the thickness of the gasket or (2) thc density ofthe gasket surface a multiplicity of relatively small gasket material,from what standard practice has compressed areas forming a force-bearingbody lll indicated as most effective in use. portion and alternatelydisposed with respect lu Greater compressibility obtained by increasingthereto, a multiplicity of relatively small more the thickness of thecushion material layers of compressible areas. When the gasket is placedthe gasket while maintaining standard density is under compression inuse, and compressed beundesirable because it objectionably aects thetween the sealing surfaces, it will have a thickl5 compression ratio ofan internal combustion enness Within the predetermined tolerance per- 15gine, and hence is impracticable from the enmitted by the bestengineering practice and the gineering standpoint. density of thegasket-'will be such as to afford Increasing compressibility bydecreasing the the required resistance to burning and blowing. densityofthe cushion material has proven dis- Thus it is seen that the 4denseportions of the 2 astrous because such gaskets under compression gasketgive the required force-bearing strength 20 in amotor were lacking bothinrequired strength and blow-out resistance, while the less dense, andcompactness to resist blowing and burning more compressible projectionsgive the gasket and did not form an effective seal. v 'the ability toconform perfectly to the irregular- This problem of increasingcompressibility ities ofthe bearing surface.

25 without increased thickness or decreased density The gasket may beproduced simply and eifec- 25 is solved by the present invention inaccordance tively either by a'single voperation of combining with whichthe efficient compression ratio of the the metal layer with the cushionlayers, or the motor is not altered, while at the same time, thecombining step may take place first followed by required strength andcompactness to afford a treatment to impart the desired compressibility3" optimum resistance in use is obtained, and the characteristic to thegasket. 30

compressibility of the gasket is such that any Another feature of thepresent invention reunevenness in the sealing surfaces due, for ex.-sides in reenforcing` and/or strengthening the ample, to motor design,warped heads, or'im gasket with gromet means formed of stainless properbolt spacing is accommodated, whereby an steel. For many purposes, Ihave discovered that effective seal is formed. the use of stainlesssteel gromets affords greater 35 Briefly, this inventionv provides agasket in resistance to blowing and burning of thegasket Which fOr anygiven Surface area including a under compression and therefore addsmaterially multiplicity of tangs.' the tangs are` bent' or deto the lifeof the product.

ected t0 Varying degrees S0 that the 6115111011 The gasket may takevarious forms other than 4" material such as asbestos in Such area 1Sdiffer- 'those new to be described, and the methods for 40 eniallyclinched at spaced DODPS. ie 111 any its manufacture may be considerablyvaried from area COISTUHE a multiphcity 0f tangs thetngs, the preferredprocedure to be later outlined hereare variably bent or the asbestosbeneath each Am withotdeparting from the spirit of this im tang isclinched to varying degrees of pressure, Vent-don. s. A'

45 Such variable bending of the tangs not only Referring wthe drawings:y 45 chnches Varla'bly the Cushion material- Flgure l is an enlargedsectional view showing beneath the Sep-ate tangs but als" provides' .athe lo retionf- 'fw initiallcombinin th met 1 differential ofcompression of the cushion ma- Dem '-0 y* g e a terial between the tangsdue to the fibrous charand cus or? layers acter of the cushion materialand the tendency Figure 2 1S an enlarged sectional View showing 50 ofthe clinching action to extend outwardly from one mean-s 0f Impartlng t0fhf'gasket Combina;- each tang. Furthermore, in addition to the difytien of Figure 1 a compress1b1l1t-y characteristic ferential ofcompression obtained by the variable in accordance with thisinVentOnbending of the tangs, there is provided a com- Figure 3 is anenlarged sectional view showing pression differential between portionsof the rela, one method of combining the metal and cushion 55 layers andsimultaneously imparting the desired compressibility characteristic tothe gasket.

Figure 4 is a sectional view of the article formed in accordance withthe two-step operation of Figuresl and 2 or the single operation ofFigure 3.

Figures 5, 6 and 7 are sectional views of modifications, and,

Figure 8 is a top elevation of a portion of a cylinder head gasket.

The invention is useful in connection with gaskets generally, but isparticularly applicable for automotive use, for example, in cylinderhead gaskets, exhaust manifold gaskets, etc.

Referring to Figure 1, I have illustrated a metal layer I0 having amultiplicity of closely spaced or compacted projections II struck uptherefrom. To opposite sides of this metal layer in combining relationare applied layers of cushion materials I2 such as asbestos of the usualstandard density. The three layers are combined as by means of opposedpressure rolls I3 having smooth surfaces, the pressure employed beingjust sufficient or light enough to eiect the permanent combination ofthe layers. The product formed by this operation is of an overallthickness greater than that of the standard gasket and hassubstantiallysmooth surfaces.

Following the combining operation, the gasket is subjected to anoperation for the purpose of (1) reducing it to standard thickness and(2) enhancing its compressibility. In this operation, as aboveexplained, (l) the tangs are Variably bent or the asbestos beneath thedifferent tangs is clinched to varying degrees of compression and at thesame time (2) there is produced a differential of compression of theasbestos between the tangs independent of the extent to which theasbestos is maintained clinched or hollows and ridges or projections.Other means may be employed to effect this result and I do `not wish tobe limited to the use of rolls although such rolls are preferred, andare highly practical.

As the sheet or combination passes between the opposed rolls I4, asshown in Figure 2. the ridges or projections of the rolls contact withthe tangs II at various points and variably compress the tangs. ThusI ina given area including a multiplicity of tangs, the tang Illa is lightlyturned over, the tang I0b is very completely bent over and clinched andthe tang IIJc is turned over slightly more than the tang Illa butsubstantially less than the tang Illb. In this many ner, the cushionmaterial beneath the tangs is subjected to varying compression as is thecushion material immediately about the tangs due to the fibrouscharacter of the asbestosmaterial and the tendency of the clinchingaction to extend outwardly from each tang. Also it will be noted thatthe cushion material is formed with a multiplicity of'closely spacedrelatively small alternately disposed hollows I1 and more compressibleprojections or ridges I8 conforming in number and contour to the ridgesand hollows I5 and I6. Thus, the cushion material between andindependent of the tangs is further subjected to varying compression.The pressure exerted by the rolls I5 and I6, of course, may be varied asdesired depending upon the gasket being formed, it being understood ofcourse, that gaskets for various motors and manifolds have different nalthicknesses and densities of cushion material.

'Ihe method just described embodies two steps, namely, (a) the combiningstep of Figure 1 and (b) the forming vstep of Figure 2.

In Figure 3, which is the preferred method. the same result is obtainedin a single step or operation using the rolls 'I5 and I6 or other meansto accomplish the desired result. The rolls I5 and I6 will be suitablyadjusted to exert the desired combining and forming pressuressimultaneously upon the three layers of material.

The product of the two step operation or the single step operation isillustrated in Figure 4 which has been sufliciently enlarged to show howthe gasket atany given area including a multiplicity of tangs has thecushion material clinched to varying degrees, the tangs being bent ordeflected to varying degrees so that the asbestos in such area isdifferentially bent at spaced points, that is, in any area containingthe multiplicity of tangs, the tangs are variably bent or the asbestosbeneath the tangs is clinched at varying degrees of compression. Asexplained, variable bending of the tangs not only clinches variably theasbestos directly beneath the separate'tangs. but moreover, provides adifferential of compression of the asbestos between the tangs due to thefibrous character of the asbestos material andthe tendency of theclinching action to extend outwardly from each tang. Also as pointedout, the invention comprehends a variable compression of `the asbestosbetween the tangs independently of the extent to which such asbestos ismaintained clinched or compressed by the tangs themselves. In otherwords, in addition to the differential of the compression obtained byvariable bending of the tangs, there is provided a differential betweenportions of lthe relatively unclinched asbestos between the tangs.

The gasket is illustrated in Figure 4 before it has been compressedbetween sealing surfaces. The thickness defined by the distance betweenthe low points or bottoms of the hollows on opposite sides of the gasketis substantially the thickness of the standard gasket and the asbestosenhanced. In actual use no weakness such as` might be causedK by burningor blowing has developed, and the gasket operates with increased."

efficiency and has a nal thickness under compression which does notinterfere with the optimum compression ratio of the motor. At the sametime, the compressible areas permit the gasket to conform to anyirregularities in the sealing surface due to motor design, warped heads,improper spacing of the bolts. etc.

As one example of a cylinder head gasket, formed as in Figure 4 andusing cushion material of standard density, the overall thickness of thegasket between the tops of the projections is about eighty thousandthsof an inch;'the thickness between the bottoms of opposite hollows issubstantially fty-iive thousandths of an inch; and the height of theridges and the depths of the hollows in the gasket is about twelve and'one-half thousandths of an inch. Under compression, in the motor, thisgasket compresses to a thickness within the tolerance allowed by theautomotive engineers for maximum efficient compression ratio of themotor, and-the gasket has the required density and enhancedcompressibility to form. a tight seal and resist blowing and burning.

In Figure 5, I have shown a gasket in accordance with this invention andwherein the cushion material I2 is applied to only one side of the metallayer I0.

In Figure 6 I have shown a gasket in which two layers of the combinedmaterial shown in Figure 5 are superposed with the metal layers incontact and a suitable gromet o1; gromets I9 are employed for connectingthe combined layers either at the peripheral edge of the gasket or atthe edges of the gasket openings or both. In Figure 7 the constructionis substantially like that shown in Figure 6 except that the cushionlayers are in contact.

.In Figure 8, I have illustrated, by way of example only, ac'ylinderhead gasketembodying the constructions shown in Figures 4 to 7.

The gromets I9 may be used with any of the gaskets herein illustratedand are preferably continuous with the peripheral edge or the edges ofthe'openings of the gasket. I have discovered that gromets made ofstainless steel produce a very enhanced result in that they or markedresistance to the heat and pressures encountered in the use of thegasket for automotive purposes.

I claim:

1. A gasket having a metal layer formed with Y 2. A gasket having4 ametal layer formed with l a multiplicity of closely spaced projections,a

lll

la'yer vof cushion material superposed o n said metal layer andcoextensive therewith, the projections of saidmetal layer being embeddedin the cushion material and clinched thereto and said projections in anygiven area being variably bent whereby the compressibility of the gasketvaries in said area.

3. A gasket' having a metal layer formed with a multiplicity of closelyspaced projections, a layer of cushion material superposed o n saidmetal layer and coextensive therewith,` the pro, jections of. said metallayer being embedded in the cushion material and clinched thereto, thecushion material beneath the projections in any given area beingvariably compressed whereby the compressibility vof the gasket varies insaid area.

a 4. -A gasket having a metal layer formed with a multiplicity ofclosely spaced projections, a layer lof cushion material superposed onsaid metal layer and coextensive therewith, the projections oi' saidmetal layer being embedded in given area being variably compressedwhereby the compressibility of the gasket varies in said area.

5. A gasket having aI metal layer formed with a multiplicity of. closelyspaced projections, layers of cushion material superposedon oppositesides of said metal layer and 'coextensive therewith, the projections ofsaid metal layer being embedded in the cushion material and clinchedthereto, the compressibilityy of the gasket varying in any given areathereof. y

6. A gasket having a service opening therethrough and comprising twoindependently preformed composite layers, each layer being formed by alamina. of, compressed cushion material and a lamina of sheet metal atleast coextensive therewith and comprising a multiplicity of closelyspaced projections extending substantially through the thickness of thecushion lamina to clinch the latter and being confined to said lamina,the projections being struck from the sheet metal layer and formingperfgrations therein through which the cushion material is exposed, thesaid composite layers being coextensive and being arranged in face toface relation with the pressure to the surfaces being sealed and theperforations therein vpermitting the cushion material to be brought tothe gasket surfaces at a multiplicity of closely spaced Ypoints and tocontact with the surfacesto be sealed when the gas- ,ket is subjected topressure, the compressibility of the gasket varying in any; given areathereof, and means independent of the projections connecting thecomposite layers.

'1. A gasket having a service opening therethrough andecomprisingI twoindependently preformed composite layers, each layer being formed by alamina oi'. compressed cushion material and a lamina oi' sheet metal atleast cxtensive therewith and comprising a multiplicity of closelyspaced projections extending substantially through the thickness of thecushion lamina to "clinch the-flatter and being confined to said lamina,the projections being struck from the sheet metal layer and formingperforations therein through which the cushion material is exposed, thesaid composite layers being coextensive and being arranged in tace toface relation with the cushion laminae exposed at the gasket surfaces,the multiplicity of perforations in each metal lamina providing metalsurfaces readily conformable under pressure to the surfaces beingsealed, the compressibility of, the gasket varying in any given areathereof, and means independent of the projections connecting thecomposite layers.,

8. A gasket having a service opening therethrough and comprising twoindependently preformed composite layers, each layer being formed by alamina of compressed cushion material and a lamina.- of sheetmetal atleast coextensive therewith and comprising a multiplicity of closelyspaced projections extending substantially through the thickness of thecushion lamina to clinch the latter and being confined to said lamina,the projections being struck from the sheet metal layer and formingperforations therein through which the cushion material is exposed, thesaid composite layers being coextensive and being arranged in face toface relation with the cushion laminae exposed at the gasket surfaces,

the multiplicity of perforations in each metal lamina providing metalsurfaces readily comformable under pressure to the surfaces beingsealed, and means independent of the projections connecting thecomposite layers, the compressibility of the gasket varying in any givenarea thereof.

9. A gasket having a metal layer formed with a multiplicity of closelyspaced projections, a layer of cushion material superposed on said metallayer and coextensive therewith, the projections of said metal layerbeing embedded in the cushion material and clinched thereto, thecompressibility of the gasket varying in any given area thereof, and astainless steel'gromet enclosing an exposed edge portion of the gasket.

10. A gasket having a. metal layer formed with a multiplicity of closelyspaced projections, a layer of cushion material superposed on said metallayer and coextensive therewith, the projections of said metal layerbeing embedded in the cushion material and clinched thereto, the cushionmaterial beneath the projections .and between the projections in anygiven area being variably compressed whereby the compressibility of thegasket varies in said area.

11. The method of making a variably compressible material having anuneven surface of varying density and containing a metallic reinforcingmember which comprises compressing together a sheet of cushion materialand a layer of metal having projections thereon and clinching saidprojections into said cushion material an unequal amount. l

12. A method as described in claim 11 wherein the cushion materialbeneath the clinched projections is variably compressed.

13. A method as described in claim 11 wherein the cushion materialbetween the clinched pro- 0 jections is variably compressed.

14. A method `as described in claim 11 wherein the cushion materialbeneath and between the clinched projections is variably compressed.

15. The method of making a variably compressible material having anuneven surface of varying density and containing a metallic reinforcingmember which comprises compressing together a sheet of cushion materialand a layer of metal having projections thereon, partially clinching allof said projections into said cushion material an .equal amount, andthen further clinching said projections unequal amounts.

16, A gasket having a metal layer formed of' a multiplicity of closelyspaced projections, a layer of cushion material superposed on said metallayer and coextensive therewith, the projections of said metal layerbeing embedded in the cushion material and clinched thereto, the wholegasket having a dense compressed forcebearing body portion and amultiplicity of less compressed and more compressible projections onthesurface thereof. A

17. A gasket as described in claim 16 wherein the area of said surfaceprojections is substantially smaller than the area of the densecompressed body portion.

18. A gasket having a metal layer formed-with a multiplicity of closelyspaced projections, a

layer of cushion material ,placed on each side* of said metal layer andcoextensive therewith, the projections of said metal layer beingembedded in the cushion material and clinched thereto, the whole gaskethaving a dense compressed force-bearing body portion and a multiplicityof less compressed and more compressible projections on the surfacethereof.

19. A gasket as described in claim 18 wherein the area of said surfaceprojections is substantially smaller than the area of the densecompressed body portion.

'GEORGE T. BALFE.

